Birthright 3E
Hey there. I'm actually running a Birthright 3E campaign. There was a dedicated fan base that actually produced a 3E conversion pdf. They obtained official permission to do so from WoTC. Not at conversion manual mind you, but a fully functioning 3E (not 3.5 but easy to convert) campaign setting. Actually very well done. There were some spelling/pdf errors in the document but they didn't effect the overall book. Plus it was free. I took the pdf to Kinkos and had them print me up (and bind) a manual. Cost me about 20 bucks.
The campaign setting is based around very small kingdoms (many of which are about 70 miles across) ruled by characters possessing divine bloodlines passed down through family generations (or obtained through ceremony and/or murder). Hence the name of the setting. These bloodlines can give the characters various powers, including things like (but not limited to) improved senses, enhanced social presence, stat boosts, resistances to various dangers, even various forms of invulnerability. These powers can be improved as well - by either drawing upon the magic of the kingdom or through ursupation (similar to Highlander).
The idea is that the PCs will pick a "home" kingdom that they either rule or serve as lieutenants for - though as many people have already pointed out, standard adventuring is more than possible. There are many plot hooks already installed (if you own the 2nd ED stuff, which I largely acquired from Ebay). Plus the game makes motivation much more easy to come by - the PCs have something to fight for (their home kingdom) right from the start. And it's a perpetual goal that can have satisfying benchmarks such as repelling invasions, improving the economy, expanding the kingdom's/guild's/temple's influence, etc. Pretty much any adventure you can think of can be worked in.
I've been running it for over a year, though our game is kinda winding down now. My campaign was based around the idea that the PCs started as lieutenants and eventually one (the heir-to-be) would take over. I structured it this way because 3E is skill based and running the kingdom calls for various checks (diplomacy, administration, etc) - I didn't want my 1st level PCs to get run-over by the other regents. Plus this allowed me to build up the campaign flavor and events, making it a more natural transition to leadership. Unfortunately, a series of PC deaths has derailed many of my storylines and we haven't gotten to the PCs taking over yet.
I like the setting very much. It provides a huge amount of information (again if you own the 2nd ED stuff) but is open enough that you can put on whatever kinda spin you want. The various iconic NPCs become well known - even more so than most campaigns (IME) because they WILL have an effect on the PCs kingdom at some point. My players hate the Baron of Ghoere, fear Rhoubhe Manslayer, and have become rather impressed with the son of The Mhor, Lord Michael. Plus the game does give a distinct feeling to each culture.
There are a couple of areas I wished were more fleshed out, however. The game can be largely centered around politics and social interaction, a well defined treatment on social structures would have been very nice to have, something to give those of us with little working knowledge of Medieval society a solid base to work from. Especially Knights. Another thing that kinda puts people off is the spelling of names and what-not. I've been told it's based on Welsh style language - in any case some people find in difficult. For example, mentioned above, Rhoubhe is pronounced "Rove". Some people like it, others loathe it. Elvish can be hellish to decipher.
The setting is low volume magic - the world is very magical, but wizards and magic items are a relative rarity. Make no mistake, magic is potent, especially realm magic, it's just not common. Also the game pulls from more "traditional" fantasy and history, which can be seen in the artwork.
The website was originally
www.birthright.net, but upon recent inspection it has undergone a major revamp. Plus I couldn't find any of the files they used to have (including the campaign book). I've heard that they are making it into a full on retail version - though I do not know for sure.
For those interested in acquiring the setting I would recommend locating the Birthright Basic Boxed Set (it has several indispensible books and maps) and as many of the Player's Secrets Kingdom guides as you can lay your hands on. Specifically Roesone, Tuornen, and Endier. One last thing, you WILL have to tweek things and make adaptations (I added between 3 to 5 levels on to most of the NPCs listed so they were more 3E compatible)
If anyone is interested, and if I can find it, I can email them the 3E campaign setting pdf (it is 8.5 megs if I remember correctly). Hope this was helpful.